This invention relates to a method of making a coated article to be used in a window unit or any other suitable application. For example, in certain embodiments this invention relates to a method of making a window unit (e.g., vehicle window such as vehicle windshield, backlite, sunroof, or sidelite, or IG window unit) including a step of heat treating a glass substrate coated with at least a layer comprising diamond-like carbon (DLC).
Vehicle windows (e.g., windshields, backlites, sunroofs, and sidelites) are known in the art. For purposes of example, vehicle windshields typically include a pair of bent glass substrates laminated together via a polymer interlayer such as polyvinyl butyral (PVB). It is known that one of the two glass substrates may have a coating (e.g., low-E coating) thereon for solar control purposes such as reflecting IR and/or UV radiation, so that the vehicle interior can be more comfortable in certain weather conditions. Conventional vehicle windshields are made as follows. First and second flat glass substrates are provided, one of them optionally having a low-E coating sputtered thereon. The pair of glass substrates are washed and booked together (i.e., stacked on one another), and then while booked are heat bent together into the desired windshield shape at a high temperature(s) (e.g., 8 minutes at about 600-625 degrees C.). The two bent glass substrates are then laminated together via the polymer interlayer to form the vehicle windshield.
Insulating glass (IG) window units are also known in the art. Conventional IG window units include at least first and second glass substrates (one of which may have a solar control coating on an interior surface thereof) that are coupled to one another via at least one seal(s) or spacer(s). The resulting space or gap between the glass substrates may or may not be filled with gas and/or evacuated to a low pressure in different instances. However, many IG units are required to be tempered. Thermal tempering of the glass substrates for such IG units typically requires heating the glass substrates to temperature(s) of at least about 600 degrees C. for a sufficient period of time to enable thermal tempering.
Other types of coated articles also require heat treatment (HT) (e.g., tempering, heat bending, and/or heat strengthening) in certain applications. For example and without limitation, glass shower doors, glass table tops, and the like require HT in certain instances.
Diamond-like carbon (DLC) is sometimes known for its scratch resistant properties. For example, different types of DLC are discussed in the following U.S. Pat. Nos. 6,303,226; 6,303,225; 6,261,693; 6,338,901; 6,312,808; 6,280,834; 6,284,377; 6,335,086; 5,858,477; 5,635,245; 5,888,593; 5,135,808; 5,900,342; and 5,470,661, all of which are hereby incorporated herein by reference.
It would sometimes be desirable to provide a window unit with a protective coating including DLC in order to protect the window from scratches and the like. Unfortunately, DLC tends to burn off at temperatures of from approximately 380 to 400 degrees C., as the heat treatment is typically conducted in an atmosphere including oxygen. Thus, it will be appreciated that DLC as a protective overcoat cannot withstand the heat treatments (HT) at the extremely high temperatures described above which are often required in the manufacture of vehicle windows, IG window units, and/or the like.
Accordingly, those skilled in the art will appreciate that a need in the art exists for a method of providing heat treated (HT) windows with a protective coating (one or more layers) comprising DLC. A need for corresponding windows also exists.
An object of this invention is to provide a method of making a coated article (e.g., window unit), including heat treatment (HT), wherein the coated article includes a coating (one or more layers) comprising diamond-like carbon (DLC).
Another object of certain example embodiments of this invention is to provide a method of making a coated article by (a) coating a glass substrate with a layer comprising DLC, then (b) forming a protective layer on the glass substrate over the DLC, and (c) heat treating the coated article with the DLC and the protective layer thereon with the protective layer preventing the DLC from burning off (in part or entirely) during the heat treatment. The resulting coated article may be used in the context of, for example and without limitation, vehicle windows, architectural windows, insulating glass (IG) window units, shower doors, glass table tops, and/or the like.
Another object of certain example embodiments of this invention is to provide a coated article (e.g., window unit) made in accordance with the above technique.
Another object of certain example embodiments of this invention is to fulfill one or more of the above-listed objects and/or needs.
In certain example embodiments of this invention, one or more of the above-listed objects and/or needs is/are fulfilled by providing a method of making an insulating glass (IG) window unit, the method comprising: providing a glass substrate; forming a layer comprising diamond-like carbon (DLC) on the glass substrate; forming a protective layer on the glass substrate over the layer comprising DLC; heat treating the glass substrate with the layer comprising DLC and the protective layer thereon so that during the heat treating the protective layer prevents significant burnoff of the layer comprising DLC, wherein the heat treating comprises heating the glass substrate to temperature(s) sufficient for thermal tempering; and after the heat treating, coupling the glass substrate with at least the layer comprising DLC thereon to another substrate in making the IG window unit.
In certain other example embodiments of this invention, one or more of the above-listed objects and/or needs is/are fulfilled by providing a method of making a vehicle windshield, the method comprising: providing a glass substrate; forming a layer comprising diamond-like carbon (DLC) on the glass substrate; forming a protective layer on the glass substrate over the layer comprising DLC; heat treating the glass substrate with the layer comprising DLC and the protective layer thereon, wherein the heat treating comprises heating the glass substrate to temperature(s) sufficient for bending the glass substrate; and after the heat treating, laminating the glass substrate with at least the layer comprising DLC thereon to another substrate via at least a polymer inclusive interlayer in making the vehicle windshield.
In still further example embodiments of this invention, one or more of the above-listed objects and/or needs may be fulfilled by providing method of making a coated article, the method comprising: providing a glass substrate; forming a layer comprising diamond-like carbon (DLC) on the glass substrate; forming a protective layer on the glass substrate over the layer comprising DLC; heat treating the glass substrate with the layer comprising DLC and the protective layer thereon, and wherein the heat treating comprises heating the glass substrate using at least temperature(s) of at least 580 degrees C. for at least one of bending and thermally tempering the glass substrate.
In yet other example embodiments of this invention, one or more of the above-listed objects and/or needs may be fulfilled by providing a coated article comprising: a glass substrate that is thermally tempered and/or bent; a layer comprising diamond-like carbon (DLC) supported by the glass substrate; and a protective layer comprising a carbide provided on the glass substrate over the layer comprising DLC. In certain example instances, the carbide may comprise at least one of: boron carbide, titanium carbide, hafnium carbide, titanium hafnium carbide, tantalum carbide, and zirconium carbide.